There are two primary sizes of ice surfaces for the playing of ice hockey, optionally within ice skating arenas, namely,                1. the North American National Hockey League (NHL) dimensions of, essentially, 200 ft. length and 85 ft. width; and        2. the International Ice Hockey Federation (IIHF) or Olympic size of 29–30 m. wide by 60–61 m. long (i.e. 95.14–98.42 ft. by 196.85–200.13 ft.).        
Thus, the main difference between the two playing surfaces is that the IIHF surface is about 10–14 ft. wider than the NHL surface. The NHL size rink is, generally, used in North America in spectator facilities; while the IIHF size rink is used in Europe.
There are many persons who have begun to question whether or not the NHL-sized ice surfaces existing in facilities should be abandoned in favour of the larger IIHF-sized surfaces because of the increased size and speed of today's hockey players and for other reasons.
However, one major problem associated with the apparently, at first sight, simple task of enlarging an existing NHL playing surface is that it is very difficult, if not impossible, to extend the cooling system which is embedded in the NHL ice surface's concrete slab base and which causes the surface ice to obtain the larger IIHF ice surface. We have conducted extensive research on extending the existing cooling pipes and concrete base by 5–7 feet in width on each side of the ice surface. Advice from leading ice surface manufacturers, skilled in the art, is that the risk level in one approach involving removing the edge of the concrete base without damaging the existing cooling pipes is too high while being probably impossible to accomplish successfully. A second alternative is to pour two new 5–7 feet strips of concrete slab with cooling pipes adjacent to the sides of the existing NHL ice surface. The problem with this solution is that it is anticipated that there will be substandard cooling where the two concrete slabs are adjacent to each other, creating poor ice conditions along two lines running the length of the ice surface, approximately 5–7 feet in from the side boards. The third solution, which would work, is to remove all of the existing NHL ice surface area and enlarge it by replacing it with a new IIHF ice surface area. However, this solution is prohibitive from a capital cost perspective.
A second major problem of enlargement is that the sightlines for the spectators in the tiers of seats adjacent the ice rink playing surface to view the ice surface are designed for the smaller NHL size. When the surface is made larger, i.e. to the IIHF size, almost all of the spectators on the sides of the ice are not able to see a significant area of the ice surface that is closest to them. Therefore, the solution of simply replacing the NHL-sized ice surface with an IIHF-sized surface is unacceptable because of the sub-standard sightlines for spectators sitting on the sides of the ice surface, particularly when many are VIP customers. An alternative solution that we investigated was to change the angle or placement of the seating tiers to achieve acceptable sightlines. This, however, would be prohibitively expensive, requiring the demolition of almost the total interior bowl of the arena on the sides of the ice surface.
For the above reasons, although there is a long felt want to effect the width enlargement of the playing surface, to-date, no spectator arena has had its ice surface converted from NHL size to IIHF size, without first removing the NHL size ice surface.
There is, therefore, a need for a practical and cost-effective method of converting an ice hockey rink from NHL dimensions to IIHF dimensions.